BANANA PROPAGATION

By Emile Amiot

FAMILY:Musaceae

SCIENTIFIC NAME:Musa
sp.

ORIGIN:Asian
tropics

DESCRIPTION :

The banana plant is a large
perennial herb with leaf sheaths that form trunk-like pseudostems. The
plant has 8 - 12 leaves that are up to 9 ft long and 2 ft wide. Root development
may be extensive in loose soil in some cases up to 30 ft laterally. Other
plant descriptions vary, it depends on the variety.

Flower development is initiated
from the true stem underground (corm) 9 - 12 months after planting. The
inflorescence (flower stalk) grows through the center of the pseudostem.
Flowers develop in clusters and spiral around the main axis. In most cultivars,
the female flowers are followed by a few "hands" of neuter flowers that
have aborted ovaries and stamens. The neuter flowers are followed at the
terminal ends by male flowers enclosed in bracts. The male flowers have
functionalstamens but aborted ovaries.

The ovaries contained in
the first (female) flowers grow rapidly, developing parthenocarpically
(without pollination) into clusters of fruits, called hands.Fruits mature in about
60 - 90 days after flowers first appear. Each bunch of fruits consists
of variable numbers of "hands" along a central stem. Each "hand" consists
of two transverse rows of fruits ("fingers").The fruit quality is determined
by size (finger length and thickness), evenness of ripening, freedom from
blemishes and defects, and the arrangement of the clusters. Quality standards
may differ in various markets.

PROPAGATION:

Propagation by division

Bananas and plantains(cultivar of Musa) are propagated
vegetatively rather than sexually because nearly all cultivated varieties
are seedless, and fruits develop parthenocarpically (in the absence of
seed development). The principal method of banana propagation by small-holder
farmers is divison of suckers or pups which arise from the base of the
main stem or from the underground corm. Farmers from different regions
prefer different size suckers for optimal planting material. Very small
pups are called buttons. Large suckers are the preferred planting material.
These are removed from vigorous clumps of banana trees with a spade when
at least three feet tall, during warm months. Pups should not be taken
until a clump has at least three to four large banana plants to anchor
it. When the pup is taken the cut must be into the mother banana plant
enough to obtain some roots. Plant close to the surface. Large leaves are
cut off of the pup leaving only the youngest leaves or no leaves at all.

Tissue Culture

Micropropagation technique has been developed
during the past two decades are now considered well established. (Banerjee
and De Langhe 1985; Cronauer and Krikorian 1984; Israeli et al.,1995; Vulysteke
1989). It has played a role in plantain and banana improvement program
world wide ( Rowe and Rosales 1996; Vulysteke et al., 1997). The rate of
multiplication ranged from two to ten or more shoots or bud propagules
per month, resulting in potential propagation rates of several thousands
or millions of plants per year.

Such rates are several orders of magnitude greater
than achievable through conventional propagation. Since it is very important
to obtain clonal plants, direct regeneration pathways has always been adopted.
However it is also important commercially that the technique employed should
be cost effective. To achieve this objective high propagation rate through
scalp techniques are used. In order to assess dwarf variants, regenerants
from scalps are assessed with GA3 and PCR methods.

The tissue culture laboratory is also used to
produce healthy banana plantlets from selected commercial varieties for
distribution to farmers using material selected from international and
local sources.Tissue culture is the most rapid method of propagation
of valuable disease-free material.

Minisetting

Minisetting is a rapid propagation techniques
which is used to quickly and inexpensively produce plant material, whether
it is banana plantlets or germinated seeds for yam production. Bananas
produced in the laboratory can be subsequently rapidly multiplied using
minisetting to make healthy plantlets available to farmers on a commercially
significant scale.